1. Field of the Invention
The present invention generally relates to the design of a mechanical assembly used in conjunction with coiled tubing and drilling tubulars for downhole operations. In particular aspects, the invention relates to devices used for connecting bottom hole assemblies together to the end of the coiled tubing or jointed pipe without the need for threaded connections, hand tools, hydraulic or mechanical make up devices, etc. It permits an end user to perform drilling and milling operations without the risk of the connection backing off, unscrewing and negates the risk of leaving the bottom hole assembly downhole. The system has two primary functions; A. at surface to eliminate the use of make-up tongs, torque wrenches, come-a-longs, load cells, or the use of hand tools to tighten the BHA together. Because there are no threads throughout the entire system therefore safety incidents such as dropped objects, injuries from hand tools, hand injuries, and the use of additional equipment and personnel at the wellhead is no longer a consideration. B. Downhole the system will eliminate the possibility of un-torquing of the assembly, parting of threads, threads salck-off/back off, etc. Remove the need for chemical locking agents such as glues or Loc-Tite compounds on threads that can also be affected by the wellbore environment.
2. Description of the Related Art
A coiled tubing bottom hole assembly (BHA) is primarily made up of check valves, disconnects, flow nozzles, hydraulic jars, mud motors, etc put together with various thread type connections; some commonly used threads are 3.5″ IF, 2⅞″ PAC and 1.500″ AMMT. These tools are deployed to perform a number of service tasks, such as milling, drilling, circulating, jarring to remove stuck equipment, placement of devices, multi-lateral entry and high deviation/horizontal wellbore intervention to name but a few applications.
The standard design for a BHA assembly or part thereof requires a constant outside diameter relative to that of the entire BHA and a common internal diameter for passage of fluid/gas and a ball drop release mechanism in the event the BHA is stuck in the wellbore and needs to be shear-released to recover the coiled tubing or drill string. The assembly includes threaded connections at the top and bottom ends and can accommodate both internal and external fishing necks for retrieval.
The deployment of BHA's in the coil tubing and drilling industry has relied heavily on threaded connections to attach each subassembly together in order to make-up a full BHA capable of performing multiple operations simultaneously.
For decades, the oil and gas industry has used threaded connections to make up toolstrings/BHAs/MHAs. Thread fatigue can result in mechanical failure of the threads, thread wear, thread back-off, un-torque, tools lost in hole and required fishing operations to retrieve out of the well. It has also resulted in injury, as when a thread is not made up properly, specifications are not adhered to, human error, surface handing equipment failure, falling objects, etc. The connection assembly of the present invention helps eliminate human error, make up/torque specifications, etc.